A system may transmit an electronic mail message, e.g., an email, from a sender to a recipient over a network. The system may operate based on a store-and-forward model in which a server stores and subsequently forwards the electronic mail message for later retrieval by the recipient. The store-and-forward model eliminates a need for the sender and the recipient to be online simultaneously. Email may be considered an asynchronous form of communication since the recipient may retrieve and reply to the electronic mail message at any time.
One disadvantage of known systems is that when the sender transmits an electronic mail message to a group of recipients, each recipient may reply to the message asynchronous from other recipients, thereby creating multiple message branches or message threads that make it difficult to clearly follow the group's discussion. As the number of message branches or message threads grow, it becomes more difficult to clearly follow the group's discussion.